/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package com.gsa.security.dataprovider;


import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.Key;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.xerces.parsers.DOMParser;
import org.apache.xml.security.encryption.EncryptedData;
import org.apache.xml.security.encryption.EncryptedKey;
import org.apache.xml.security.encryption.XMLCipher;
import org.apache.xml.security.keys.KeyInfo;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

/**
 * This sample demonstrates how to encrypt data inside an xml document.
 *
 * @author Vishal Mahajan (Sun Microsystems)
 */
public class Encrypter {

    /** {@link org.apache.commons.logging} logging facility */
    static org.apache.commons.logging.Log log = 
        org.apache.commons.logging.LogFactory.getLog(
            Encrypter.class.getName());

    static {
        org.apache.xml.security.Init.init();
    }

    @SuppressWarnings("deprecation")
	private static SecretKey GenerateAndStoreKeyEncryptionKey()
        throws Exception {

        String jceAlgorithmName = "DESede";
        KeyGenerator keyGenerator =
            KeyGenerator.getInstance(jceAlgorithmName);
        SecretKey kek = keyGenerator.generateKey();

        byte[] keyBytes = kek.getEncoded();
        File kekFile = new File("kek");
        FileOutputStream f = new FileOutputStream(kekFile);
        f.write(keyBytes);
        f.close();
        System.out.println(
            "Key encryption key stored in " + kekFile.toURL().toString());

        return kek;
    }

    private static SecretKey GenerateDataEncryptionKey() throws Exception {

        String jceAlgorithmName = "AES";
        KeyGenerator keyGenerator =
            KeyGenerator.getInstance(jceAlgorithmName);
        keyGenerator.init(128);
        return keyGenerator.generateKey();
    }

    @SuppressWarnings("deprecation")
	private static void outputDocToFile(Document doc, String fileName)
        throws Exception {
        File encryptionFile = new File(fileName);
        FileOutputStream f = new FileOutputStream(encryptionFile);

        TransformerFactory factory = TransformerFactory.newInstance();
        Transformer transformer = factory.newTransformer();
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(f);
        transformer.transform(source, result);

        f.close();
        System.out.println(
            "Wrote document containing encrypted data to " +
            encryptionFile.toURL().toString());
    }

//    public static void main(String unused[]) throws Exception {
public void initiate(byte[] soapmsg)throws Exception{
/*    	String xmlFile = "D:/SDG-Internal/Projects/Werbservices/XMLEncryptor/x1.xml";
    	DOMParser parser = new DOMParser();

        try {
            parser.parse(xmlFile);

        } catch (SAXException se) {
            se.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }*/
	
	InputStream in = new ByteArrayInputStream(soapmsg);
        DocumentBuilderFactory factory = null;
        DocumentBuilder builder = null;
        Document document = null;

        try {
          factory = DocumentBuilderFactory.newInstance();
          builder = factory.newDocumentBuilder();
        } catch (ParserConfigurationException e) {
          e.printStackTrace();
        }

        try {
        	document = builder.parse(new InputSource(in));
        } catch (SAXException e) {
          e.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        }
      
      //  Document document = parser.getDocument(new InputSource(in);
        
    	//Document document = (Document)new ByteArrayInputStream(soapmsg);
 //new BufferedInputStream();//createSampleDocument();

        /*
         * Get a key to be used for encrypting the element.
         * Here we are generating an AES key.
         */
        Key symmetricKey = GenerateDataEncryptionKey();

        /*
         * Get a key to be used for encrypting the symmetric key.
         * Here we are generating a DESede key.
         */
        Key kek = GenerateAndStoreKeyEncryptionKey();

        String algorithmURI = XMLCipher.TRIPLEDES_KeyWrap;

        XMLCipher keyCipher =
            XMLCipher.getInstance(algorithmURI);
        keyCipher.init(XMLCipher.WRAP_MODE, kek);
        EncryptedKey encryptedKey =
            keyCipher.encryptKey(document, symmetricKey);

        /*
         * Let us encrypt the contents of the document element.
         */
        Element rootElement = document.getDocumentElement();

        algorithmURI = XMLCipher.AES_128;

        XMLCipher xmlCipher =
            XMLCipher.getInstance(algorithmURI);
        xmlCipher.init(XMLCipher.ENCRYPT_MODE, symmetricKey);

        /*
         * Setting keyinfo inside the encrypted data being prepared.
         */
        EncryptedData encryptedData = xmlCipher.getEncryptedData();
        KeyInfo keyInfo = new KeyInfo(document);
        keyInfo.add(encryptedKey);
        encryptedData.setKeyInfo(keyInfo);

        /*
         * doFinal -
         * "true" below indicates that we want to encrypt element's content
         * and not the element itself. Also, the doFinal method would
         * modify the document by replacing the EncrypteData element
         * for the data to be encrypted.
         */
        xmlCipher.doFinal(document, rootElement, true);

        /*
         * Output the document containing the encrypted information into
         * a file.
         */
        outputDocToFile(document, "encryptedInfo2.xml");
    }
}
